(a) For the purpose of establishing accounts in Amistad and Falcon Reservoirs, the two reservoirs are considered to constitute a single storage system. Accounts in the Lower and Middle Rio Grande are based upon a water right's annual authorization in acre-feet. Water rights for irrigation and mining purposes are considered as having irrigation priority rights and therefore are included in the irrigation accounting system.
(b) When there is adequate water to do so, the watermaster shall maintain the following accounts:
  (1) a reserve of 225,000 acre-feet of water for domestic, municipal, and industrial uses;
  (2) an operating reserve of 75,000 acre-feet;
  (3) the accounts for irrigation uses and all other uses.
(c) The operating reserve is necessary to cover losses of water charged to the United States. These losses are the result of seepage, evaporation, and conveyance; emergency requirements; and adjustments of amounts in storage as may be necessary by finalization of provisional computations by the International Boundary and Water Commission.
(d) Water-in-transit accounts are not eligible for an allocation under §303.22 of this title (relating to Allocations to Accounts) and are regulated under Subchapter I of this chapter (relating to Rio Grande Bed and Banks Permits for Water-in-Transit) and Subchapter J of this chapter (relating to Administration of Rio Grande Bed and Banks Permits for Water-in-Transit).

Source Note: The provisions of this §303.21 adopted to be effective July 2, 1986, 11 TexReg 2890; amended to be effective April 26, 2001, 26 TexReg 3013; amended to be effective October 26, 2006, 31 TexReg 8716